Textile-type glass fibers have been manufactured for many years. In producing continuous strand type textile fiber glass, a plurality of individual or monofilament, glass fibers, substantially comtemporaneous with forming, are in a converging manner brought into contact with an applicator wherein a size is applied to the glass fibers. Subsequent to the application of the size, the strand of individual glass fibers is then wound by suitable winding means into a package and the package is dried. Such fibers are typically employed for numerous reinforcement purposes. In one typical use of such fibers, after drying the fibers are chopped, into so-called chopped strands, and these chopped strands are converted into an aqueous slurry and applied to a paper type forming machine. The water is then removed and an appropriate binder is applied to the de-watered blanket of fibers. Such binder is a thermosettable polymer and is heated to cure it. The resulting product is termed a wet process mat and finds numerous applications. If desired, such wet process mat may then be coated or impregnated with asphalt and this product finds utility in the roofing industry. Alternatively, instead of applying a thermosetting binder, the chopped strands, after removal of water, may be coated with asphalt.
While asphalt itself has many desirable properties, especially its low cost, when it is employed as a size in the production of continuous strands of glass fibers, this asphalt is highly soluble in various solvents. Consequently, such use of asphalt as a size is not satisfactory.Similarly, when asphalt is employed with, for example, wet process mat to produce a reinforcement for roofing applications, that asphalt likewise is solvent soluble, thus handicapping some of its utility and methods of application.
In German Offenlegungsschrift No. 28 42 355, a chemically modified asphalt is taught. This chemically modified asphalt is the reaction product of asphalt, a vinyl aromatic monomer, for example, styrene, and a rubber. This publication teaches that when glass fibers are coated with such a chemically modified asphalt, the material can be insolubilized by an optional heating step carried out at temperatures in the range of about 200.degree. to 500.degree. F. (93.degree. to 260.degree. C.). Unfortunately, however, it will be appreciated that because of the chemical reaction which is needed to obtain the chemically modified asphalt, the cost of that material is increased relative to an asphalt which has not been chemically modified and, additionally, the materials used, i.e., the rubber and styrene, are commonly more expensive than asphalt. Consequently, the obtainment of the insolubilized chemically modified asphalt coating is penalized because of cost considerations.